?try ?tryCatch On Mar 24, 2009, at 6:04 PM, Dan Kortschak wrote:
Hi Jorge, That is exactly what I wanted - I should have given a reasonable number of observations (my set has *almost* all paired observations, so it will still break with that approach unless I manicure the data set). Is there a way to fail nicely on a single one of the tests without the whole thing failing? again, thanks for your help Dan On 25/03/2009, at 7:46 AM, Jorge Ivan Velez wrote:# Data set.seed(1) x<-sample(1:3,100,replace=TRUE) y<-sample(1:20,100,replace=TRUE) z<-rnorm(100) Data<-data.frame(x,y,z) # Observations for Type and Class with(Data, table(x,y)) # Splitting the data by Class SD<-with(Data,split(Data,y)) res<-lapply(SD, function(.data){ # Type combinations by Class combs<-t(combn(sort(unique(.data[,1])),2)) # Applying the t-test for them apply(combs,1, function(.r){ x1<-.data[.data[,1]==.r[1],3] # select third column x2<-.data[.data[,1]==.r[2],3] # select third column tvalue<-t.test(x1,x2) res<-c(tvalue$statistic,tvalue$parameter,tvalue $p.value) names(res)<-c('stat','df','pvalue') res } ) } ) res
David Winsemius, MD Heritage Laboratories West Hartford, CT ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.

